IOWA ACADEMY OF SCIENCES. 37 



evolution could not stay its progress. Opinions are liable to 

 be wrong, and they are, at best, things of a day. They must 

 be changed in accordance with later developments. If there 

 is one lessoa that science has had occasion to learn, it is that 

 of the dynamics of thought, and the evolution of all science. 

 The lesson of tolerance and hospitality tDward new ideas is a 

 difficult one, but it has been largely mastered by men of 

 science, and the influence has gone over to the realms of 

 thought. Men are gradually learning the lessoa of science 

 and history, and are regarding their own platforms as only 

 stages in the great on-march of opinion. 



Another great contribution that science has made to thought, 

 lies in the prominence it has given to the inductive method. 

 It would be a serious error to suppose that a lyi'iori m-thods 

 have not played an important part in the advancement of 

 science. Many great conceptions of science of to-day had 

 their origin as speculations, but science has refused to stop 

 with speculations. Using spsculations only as sug;gestive 

 hypotheses, it has passed on to the firm establishment of its 

 doctrines by the accumulation and orderly arrangement of facts 

 of observation and experiment. It took long for science to 

 extricate itself from the Nature Philosophy of the eighteenth 

 century. To the philosophers of that day, the system and 

 methods of nature were things to be explained, a loHori, on the 

 basis of certain postulates; to the poets they were to be dis- 

 covered by a sort of divination It is safe to say there will be 

 no more systems of Nature Philosophy proposed by sane men. 

 Its problems have been relegated to the rigid methods of 

 science. There is no question that the f ruitfulness of the 

 scientific method has reacted upon almost every branch of 

 learning. We have but to point to the laboratory Psychology 

 and to the statistical methods of Political Science and Sociology 

 as illustrations. 



The greatest influence that science has contributed to 

 thought since the time of Copernicus and Newton is that of 

 evolution. Of evolution in itself there is no occasion to speak 

 in this place. The idea of evolution is revolutionizing the 

 thought of the world. We are not here to deny the rise of the 

 historical spirit in many departments of thought near the 

 beginning of this century, but there is no doubt that the spirit 

 has had its support and encouragment in the solid achievements 

 of the evolutionary idea in natural science. No other idea has 



